Synthesis and electrochemical performance of NiO/Fe3O4/rGO as anode material for lithium ion battery

NiO/Fe 3 O 4 /rGO composite materials were successfully obtained via a solvothermal route and characterized by charge/discharge test, TEM, XRD, SEM, EIS, HRTEM, XPS, CV, etc. The results showed that the Fe 3 O 4 nanospheres have an average size around 150 nm, NiO is relatively larger (about 300 nm) and agglomerated by rod-shaped particles. The nanospheres of Fe 3 O 4 and rod-shaped NiO particles were distributed on the surface of reduced grapheme oxide. The BET specific surface and BJH desorption average pore diameter of NiO/Fe 3 O 4 /rGO are 497.26 m 2  g −1 and 1.23 nm, respectively, so it improves the contact area between electrode materials and electrolyte, make ion diffusion path shorter and facilitates ion insertion/desertion. Discharge capacity was 841 mAh g −1 at the first cycle and maintain 647 mAh g −1 after 200 cycles at the current density of 500 mA g −1 , and even at the current density of 1000 mA g −1 , the discharge capacity can keep 582 mAh g −1 after 200 cycles with a well Coulombic efficiency and retention. And electrochemical impedance of NiO/Fe 3 O 4 and NiO/Fe 3 O 4 /rGO is 110 Ω and 75 Ω, respectively, indicating that the material has a good ionic conductivity.